While iodine has heretofore been widely recognized as a highly effective germicide, it has not been previously possible to prepare a soap-based surgical scrub in which iodine can be used because of the reaction which readily occurs between iodine and regular soap bases, that are usually made from tallow, coconut oil, oleic acid, palm oil, palm kernel oil and the like.
While such a reaction is obviously disadvantageous for purposes of preparing a soap-based antiseptic solution containing iodine, it has for many years provided a major method for determining the unsaturation in a fat, oil or cosmetic ingredient which is reported as the "iodine value" (See: U.S. Pat. No. XXI, 1201). In this reaction, free iodine combines in a stoichiometric reaction with unsaturated double bonds, i.e., an iodine molecule reacts with one double bond. Because of this well known reaction and because iodophores, in aqueous solution, releases free iodine (I.sup.-) for reaction with unsaturated bonds to form a non-germicidal iodide, the industry has been led away from any attempt to develop a soap-based product incorporating iodophores. Indeed the Federal Register, Vol. 43, No.4, Friday, Jan. 6, 1978, p.1236 states that "Neither the Commissioner nor the panel was presented any data to show that iodine (elemental) or iodophores can be formulated into antimicrobial soaps".
Instead, the art was forced to deliver iodine in dilute aqueous solutions and the iodine-containing surgical scrubs had to be formulated with synthetic detergents, i.e., saturated surfactants which can be relatively harsh on human skin. Representative of such detergents are: polyoxyethylene-9-octyl phenyl ether (CTFA name, "Octoxynol-9"; TRITON-X100), and sodium lauryl sulfate, sodium lauryl ether sulfate, and sodium olefin sulfonates.
The marked disadvantages of the detergent systems, especially when applied to tender and wounded areas of the human body, has been well documented (See: "Comparison of Detergent Based Versus Soap Based Liquid Soaps" by D. W. Dyer and T. Hassapis, Soap/Cosmetics/Chemical Specialties, July, 1983).
Other antimicrobial agents have been tried in soap and detergent bases with some success, but still many problems remain. For instance, cationic quaternary ammonium compounds are incompatible with anionic surfactants such as soaps. Hexachlorophene was an outstanding germicide and served the health care industry well for many years, but in 1972 was limited to use in prescription products. Other antimicrobials used in bar soaps include 3,4,4'trichlorocarbanilide (TCC); 3,4',5-tribromosalicylanilide (TBS); 4,4'-dichloro-3'-(trifluoromethyl) carbanilide; and 2-hydroxy 2', 4,4'-trichlorodiphenyl ether ("Irgasan DP-300" or "Triclosan"). However, in the early 1970's the U.S. Food and Drug Administration removed both hexachlorophene and TBS from the general market. Presently only two antimicrobial agents are successfully used in soaps, viz, TCC and Irgasan. TCC is used only in bar soaps because it is too insoluble and unstable for formulation in liquid soaps such as surgical scrubs.
The present invention thus provides a highly effective antibacterial soap composition which delivers iodine as the active germicide to the desired site in a novel soap base which enables the user to obtain the beneficial mildness of a soap base vis-a-vis the harsher detergent bases heretofore required, while simultaneously realizing the decided germicidal advantages of an iodophore.